Upright vacuum cleaner with cyclonic airflow

ABSTRACT

An upright vacuum cleaner (A) includes an upright housing section (B) and a nozzle section (C). A cyclonic airflow dirt and dust separating chamber ( 54 ) is defined in said upright housing section. A suction source (E) pulls air and entrained dirt, dust, and other contaminants through a main suction opening ( 26 ) formed in the underside ( 24 ) of the nozzle and into the cyclonic airflow chamber ( 54 ). The cyclonic airflow chamber causes the suction airstream to travel in a cyclonic path such that the entrained contaminants are separated therefrom and deposited into a dirt container ( 52 ) that defines the lower portion of the chamber ( 54 ). A main filter element ( 11 ) filters residual contaminants from the suction airstream between the chamber and the suction source. The main filter element is preferably made from high-density polyethylene porous filter media. A final filter assembly (F) filters the section airstream discharged by the suction source to ensure that the air discharged into the atmosphere is contaminant free, including those contaminants introduced into the airstream by the suction source itself.

This is a continuation-in-part of application Ser. No. 09/044,999, filedJan. 9, 1998.

BACKGROUND OF THE INVENTION

The present invention relates to vacuum cleaners. More particularly, thepresent invention relates to upright version cleaners used forsuctioning dirt and debris from carpets and floors.

Upright vacuum cleaners are ubiquitous. They are known to include anupper portion having a handle, by which an operator of the vacuumcleaner may grasp and maneuver the cleaner, and a lower cleaning nozzleportion which travels across a floor, carpet, or other surface beingcleaned. The upper portion is often formed as a rigid plastic housingwhich encloses a dirt and dust collecting filter bag, although the upperportion may simply be an elongated handle with the filter bag, and anexternal cloth bag, being hung therefrom. The cleaning nozzle ishingedly connected to the upper handle portion such that the upperportion is pivotable between a generally vertical upright storageposition and an inclined operative position. The underside of the nozzleincludes a suction opening formed therein which is in fluidcommunication with the filter bag.

A vacuum or suction source such as a motor and fan assembly is enclosedeither within the nozzle portion or the upper portion of the cleaner.The vacuum source generates the suction required to pull dirt from thecarpet or floor being vacuumed through the suction opening and into thefilter bag. A rotating brush assembly is typically provided in proximitywith the suction opening to loosen dirt and debris from the surfacebeing vacuumed.

To avoid the need for vacuum filter bags, and the associated expense andinconvenience of replacing the bag, another type of upright vacuumcleaner utilizes cyclonic airflow, rather than a filter bag, to separatea majority of the dirt and other particulates from the suctionairstream. The air is then filtered to remove residual particulates,returned to the motor, and exhausted.

Such prior cyclonic airflow upright vacuum cleaners have not been foundto be entirely effective and convenient to use. For example, with theseprior cyclonic airflow vacuum cleaners, the process of emptying dust anddirt from the cyclonic chamber dirt collection container has been foundto be inconvenient, and often resulted in the spillage of the cupcontents. Likewise, with these prior units, replacement of the filterelement has not been convenience. Other cyclonic airflow vacuum cleanershave been found to exhaust air which is not free of residualcontaminants. For example, one prior unit filters the airstream after itpasses through the cyclonic chamber, but thereafter passes the airstreamthrough the motor assembly where it is potentially recontaminated by themotor assembly, itself, prior to its being exhausted into theatmosphere.

Because the cyclonic action of such vacuum cleaners does not completelyremove all dust, dirt, and other contaminants from the suctionairstream, it is necessary to include a filter downstream from thecyclonic chamber. As such, prior cyclonic airflow vacuum cleaners haveheretofore included conventional filter elements including conventionalmedia to filter the airstream after it passes through the cyclonicchamber. These prior filter elements have caused considerabledifficulties. A conventional filter that is sufficiently fine to filterthe airstream effectively unduly restricts airflow and decreases theeffectiveness of the cyclonic action. On the other hand, a coarse filterdoes not effectively filter the airstream of residual contaminants.Further, conventional filter media, such as paper or fibrous media, hasbeen found to clog readily, thereby unduly decreasing airflow rates overtime. Thus, a need has been found for a cyclonic airflow vacuum cleanerwith an effective filter positioned downstream relative to the cyclonicchamber for effectively filtering the airstream without clogging.

Accordingly, it has been deemed desirable to develop a new and improvedupright vacuum cleaner which would overcome the foregoing difficultiesand others while providing better and more advantageous overall results.

SUMMARY OF THE INVENTION

According to the present invention, a new and improved upright vacuumcleaner is provided.

In accordance with a first aspect of the invention, a vacuum cleanerincludes a housing defining a cyclonic airflow chamber for separatingcontaminants from a suction airstream. The housing includes a floor, atop wall, a suction airstream inlet, and a suction airstream outlet. Thesuction airstream inlet and outlet are both in fluid communication withthe cyclonic airflow chamber. A suction opening is defined on thehousing. The suction opening is fluidically connected with the cyclonicairflow chamber inlet. An airstream suction source is located on thehousing. The suction source has an inlet fluidically connected to saidcyclonic airflow chamber outlet and a suction source exhaust outlet. Thesuction source selectively establishes and maintains a suction airstreamfrom the section opening to the suction source exhaust outlet. A mainfilter support extends upwardly from the floor of the housing forreleasably securing a main filter element centrally in the cyclonicairflow chamber, and a main filter element is secured thereto. A dirtcup is selectively positioned in the housing. The main filter element ispositioned in the dirt cup.

In accordance with another aspect of the invention, an upright vacuumcleaner is provided.

The vacuum cleaner includes an upright housing section including ahandle. A nozzle base section is hingedly interconnected with theupright housing section and includes a main suction opening formed in anunderside thereof. A cyclonic airflow chamber is defined in the uprighthousing section and separates dust and dirt from a suction airstream. Asuction source is located in one of the upright section and the nozzlebase section and has a suction airflow inlet in fluid communication withthe cyclonic chamber and a suction airflow outlet. A main filter elementis located in the cyclonic residual dust and dirt from a suctionairstream passing through the cyclonic airflow chamber. The main filterelement extends upwardly within the cyclonic airflow chamber from afloor of said housing section. The lower portion of the cyclonic airflowchamber is defined by a dirt container for receiving and retaining dirtand dust separated from the suction airstream.

In accordance with a further aspect of the invention, a vacuum cleaneris provided.

The vacuum cleaner includes a nozzle section A housing section isconnected to the nozzle section and is in fluid communication with thenozzle section. A cyclonic airflow chamber is located in the housingsection for separating dirt and dust from a suction airstream flowinginto the housing section between an inlet located at a periphery of thehousing section and an outlet located along a longitudinal centerline ofthe housing section. An upper conduit depends from a top wall of thecyclonic airflow chamber and includes a passage therein in communicationwith the cyclonic airflow chamber outlet. A main filter element extendsupwardly from a floor of the cyclonic airflow chamber in a centralportion of the chamber so that an annulus is defined between the mainfilter element and the housing. The main filter element filter issealingly engaged with the outlet passage in the upper conduit and isadapted for filtering residual dust and dirt from the suction airstreamprior to the suction airstream exiting the cyclonic airflow chamber.

One advantage of the present invention is the provision of a new andimproved vacuum cleaner.

Another advantage of the invention is found in the proversion of avacuum cleaner with a cyclonic airflow chamber through which the suctionairflows for separating dust and dirt from the airstream and fordepositing the separated dust and dirt into an easily and convenientlyemptied dirt cup.

Still another advantage of the present invention resides in theprovision of a cyclonic airflow upright vacuum cleaner with a mainfilter that effectively filters residual contaminants from the suctionairstream between the cyclonic airflow chamber and the motor assemblywithout unduly restricting airflow and without premature clogging.

Yet another advantage of the invention is the provision of a cyclonicairflow upright vacuum cleaner with a final filter located downstreamfrom the suction motor assembly for filtering the suction airstreamimmediately prior to its exhaustion into the atmosphere.

A further advantage of the invention is the provision of a vacuumcleaner with a main filter, an auxiliary filter, and a final filterwherein the main, auxiliary, final filters are easily removable andreplaceable.

A still further advantage of the present invention is the provision of avacuum cleaner with a filter element mounted in a filter housing whereinthe filter element and filter housing cooperate to provide a tortuousflow path for air flowing therethrough.

A yet further advantage of the present invention is the provision of avacuum cleaner with a cyclonic airflow chamber wherein accumulated dustand dirt in the chamber act to further filter at least a portion of thesuction airstream passing through the chamber.

An additional advantage of the present invention is the provision of avacuum cleaner with a cyclonic airflow chamber and main filter element,wherein the main filter element is positioned in a removable dirt cuppartially defining the cyclonic airflow chamber for ease of emptying thedirt cup and cleaning the filter.

Still other benefits and advantages of the invention will becomeapparent to those skilled in the art upon reading and understanding thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take form in certain components and structures,preferred embodiments of which will be illustrated in the accompanyingdrawings wherein:

-   -   FIG. 1 is a perspective view illustrating a cyclonic airflow        upright vacuum cleaner in accordance with the present invention:

FIG. 2 is a front elevational view of the vacuum cleaner illustrated inFIG. 1;

FIGS. 3 and 4 are left and right side elevational views, respectively,of the vacuum cleaner shown in FIG. 1;

FIG. 5 is a rear elevational view of the vacuum cleaner of FIG. 1,further showing the required suction hose assemblies in broken lines forclarity;

FIG. 6 is a bottom plan view of the vacuum cleaner of FIG. 1;

FIG. 7 is a front elevational view of the upright body portion of thevacuum cleaner of FIG. 1;

FIG. 8 is a partial side view in cross-section of the vacuum cleanerillustrated in FIG. 1, and further diagrammatically illustrating thesuction airstream flow;

FIG. 9 is a perspective view of the upright body portion shown in FIG.7, with the dirt cup and main filter housing removed for clarity;

FIG. 10 is an exploded perspective view of the main filter, main filterhousing, and dirt cup;

FIG. 11 is a perspective view of the final filter assembly in accordancewith the present invention;

FIGS. 12A and 12B are rear elevational and bottom plan views,respectively, of the upper portion of the main filter housing;

FIG. 13A is a perspective view of a main filter in accordance with thepresent invention;

FIG. 13B is a bottom plan view of the main filter;

FIG. 13C is a cross-sectional view of the main filter along line C—C ofFIG. 13B;

FIG. 13D is a cross-sectional view of an alternative main filter elementin accordance with the present invention;

FIG. 14 is a front elevational view, partially in cross-section alongline E—E of FIG. 8, illustrating the upright body portion of the vacuumcleaner of FIG. 1;

FIG. 15 is a side elevational view in cross-section of a vacuum cleanerwith cyclonic airflow in accordance with a second preferred embodimentof the present invention showing airflow through the cyclonic airflowdust and dirt separating chamber;

FIG. 16 is an exploded perspective view of an upper housing member andassociated upper conduit of the vacuum cleaner of FIG. 15;

FIG. 17 is a cross-sectional view of the upper housing member andconduit of FIG. 16;

FIG. 18 is a perspective view of the upper conduit of FIG. 16;

FIG. 19 is an exploded perspective view of a dirt cup, filter and filtermount means as employed in the vacuum cleaner of FIG. 15; and

FIG. 20 is a rear elevational view of the dirt cup, filter and filtermount means of FIG. 19 in an assembled condition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the FIGURES, wherein the showings are for purposes ofillustrating preferred embodiments of the invention only and not forpurposes of limiting the same, FIGS. 1-6 illustrate and upright vacuumcleaner A including an upright housing section B and a nozzle basesection C. The sections B,C are pivotally or hingedly connected throughthe use of trunnions or another suitable hinge assembly D so that theupright housing section B pivots between a generally vertical storageposition (as shown) and an inclined operative position. Both the uprightand nozzle sections B,C are preferably made from conventional materialssuch as molded plastics and the like. The upright section B includes ahandle 20 extending upward therefrom by which an operator of the vacuumA is able to grasp and maneuver the vacuum.

During vacuuming operations, the nozzle base C travels across the floor,carpet, or other subjacent surface being cleaned. The underside 24 (FIG.6) of the nozzle includes a main suction opening 26 formed therein whichextends substantially across the width of the nozzle at the front endthereof. The main section opening 26 is in fluid communication with thevacuum upright body section B through a passage 30 and a connector hoseassembly 34 (FIG. 5). A rotating brush assembly 36 is positioned in theregion of the nozzle main suction opening 26 for contacting andscrubbing the surface being vacuumed to loosen embedded dirt and dust. Aplurality of wheels 38 support the nozzle on the surface being cleanedand facilitate its movement thereacross.

The upright vacuum cleaner A includes a vacuum or suction source forgenerating the required suction airflow for cleaning operations. Withreference particularly to FIGS. 5 and 9, a suitable suction source, suchas an electric motor and fan assembly E, generates a suction force in asuction inlet 40 and an exhaust force in an exhaust outlet 42. The motorassembly airflow exhaust outlet 42 is in fluid communication with adownstream final filter assembly F for filtering the exhaust airstreamof any contaminants immediately prior to its discharge into theatmosphere. The motor assembly suction inlet 40, on the other hand, isin fluid communication with an upstream elongated suction conduit 46which extends upward from the motor/fan assembly E to an upper region ofthe upright section B where it communicates with the cyclonic suctionairflow dust and dirt generating region G of the vacuum A to generate asuction force therein.

With reference particularly to FIGS. 7 and 8, the cyclonic suctionairflow dust and dirt separating region G housed in the upright sectionB includes a main filter housing assembly 50 and a mating dust and dirtcup or container 52. The sections 50,52 together define a generallycylindrical cyclonic airflow chamber 54.

It may be seen with reference also to FIG. 10 that the main filterhousing assembly 50 is, itself, constructed from two mating sections—anupper fixed housing section 50a, and a lower, detachable filter housingsection 50b. The lower detachable filter housing section 50b receivesand retains a main filter element or cartridge H. The filter housingsection 50b releasably connects with the upper housing section 50a tosecure the filter element H in an operative filtering position. Moreparticularly, the section 50b includes a plurality of tabs or tangs 54bextending therefrom. Likewise, with reference also to FIG. 12B, it isshown that the upper housing section 50a includes mating tabs or tangs54a. Thus, those skilled in the art will recognize that the components50a,50b connect in a key-like fashion upon rotation of the filterhousing section 50b in relation to the upper housing section 50a so thata filter element H is operatively secured in position. Of course, ratherthan the mating tabs 54a,54b, the two housing sections 50a,50b mayalternatively include mating threads, clips, or other suitablecooperating fastening means. The filter housing section 50b includes aplurality of apertures, slots, or other passages 56 formed therethrough,preferably in the lower half thereof, so that the suction airstreamflows freely from the chamber 54 into the filter housing section 50b andto the main filter element II.

The housing upper section 50a includes a suction airflow outlet passage60 (FIG. 8) which communicates with the cyclonic chamber 54 through anaperture 62. The outlet passage 60 also communicates with the elongatedsuction conduit 46 leading to the motor/fan assembly E when the mainfilter housing assembly 50 is operatively connected to the vacuumupright section H. FIGS. 8 and 9 show that the elongated suction conduit46 extends from the motor/fan assembly E upward to communicate with themain filter housing suction outlet passage 60 so that the suction inletof the motor/fan assembly E is able to fluidically communicate with thecyclonic chamber 54. When the main filter housing assembly 50 isassembled and in the operative position as described, a mouth 66 (FIG.10) of the filter element H mates with the periphery of the aperture 62in a fluid-tight relationship. As such, the suction airflow from thecyclonic chamber 54 to the motor/fan assembly suction inlet 42 is notable to bypass the main filter element H, but instead must passtherethrough and be filtered of residual contaminants. It is preferablethat the aperture 62, and thus the main filter element H be centrally inthe cyclonic chamber 54 to facilitate the cyclonic airflow in thechamber.

The suction airstream enters an upper portion of the cyclonic dust anddirt separation chamber 54 through a generally tangential suctionairstream inlet 80. In the preferred embodiment, as shown in FIGS.12A-12B, the cyclonic chamber airstream inlet 80 is formed in the uppersection 50a of the main filter housing assembly 50. It is noted that theinlet 80 is disposed entirely on one side of a center line 81 of theupper housing section so as to induce a swirling flow around the filterhousing section 50b. The suction airstream inlet 80 of the chamber 54 isin fluid communication with a suction airstream hose 82 through afitting 84. As shown in FIG. 5, the hoses 82,34 are fluidicallyconnected via fitting 86. As such, the main suction opening 26 formed inthe nozzle underside 24 is in the fluid communication with the cyclonicchamber 54 through the passage 30, the hoses 34,82, and the cyclonicchamber suction inlet 80.

The dirt cup or container 52 of the cyclonic airflow dust and dirtseparating assembly G is constructed for large capacity and ease ofemptying the contents as necessary. In FIG. 8, it may be seen that thedirt container 54 defines over ½ the volume of the cyclonic chamber 54.As such, the capacity of the container 52 is a maximized to lengthen theoperational time before the dirt container 52 must be emptied.Furthermore, the dirt container 52 is preferably at least partiallytransparent so that an operator of the vacuum is able to view the levelof dirt and dust accumulated therein for purposes of determining whenthe dirt container should be emptied.

The dirt container 52 is connected to the vacuum upright section Bthrough use of a hinge assembly 90 which allows the dirt container 52 topivot as indicated by the arrow 1 between an operative upright positionand an open forwardly tilted position. As shown herein, the hinge 90comprises a first component 92 connected to the dirt container 52 and asecond mating component 94 formed on the upright section B. Once thedirt container 52 is pivoted to the open position, it may be pulledupward and away from the section B and separated therefrom for ease ofemptying the dirt container. Of course, after the dirt container isemptied, the foregoing procedure is reversed so that the dirt containeris once again in the operative position. A handle 96 is provided on theexterior of the container 52 to facilitate operator movement of thecontainer between the operative, open, and removed position. Aresiliently biased latch 98 retains the dirt container in the operativeposition. The latch 98 is biased through use of a spring or otherresilient member, or via the natural resiliency of the plastic fromwhich it is molded.

With continuing reference to FIG. 8, the dirt container upper edge 100defining an open upper end of the container 52 is preferably inclineddownwardly in the direction away from the handle 96 on front of thecontainer 52. The main filter housing assembly section 50 is formed witha complimentary mating inclined edge 102, and a seal such as a gasket orother structure (not shown) is provided between the edges 100,102 toprevent air leakage into the cyclonic airflow chamber 54. The inclinedupper edge 100 of the dirt container 52 also ensures that, when thecontainer is pivoted to the open position, the upper edge 100 lies in asubstantially horizontal plane. As such, the contents of the containerare much less likely to spill when the container is opened duringemptying operations. Preferably, the angle at which the upper edge 100is inclined from horizontal is selected, in combination with the maximumdistance the container is able to be pivoted on the arc 1 when opened,such that when the container is fully opened, the upper edge lies in asubstantially horizontal plane.

As is shown in FIGS. 13A-13C, the main filter element II is preferablygenerally frusio-conical in overall configuration, converging in thedirection away from the filter mouth 66 toward an opposite filter end110. However, those skilled in the art will recognize that a cylindricalor other filter configuration may be advantageously employed withoutdeparting from the scope and overall intent of the invention.

The preferred filter media comprises Porex® brand high densitypolyethylene-based open-celled porous media available commercially fromPorex Technologies Corp., Fairburn, Ga. 30213, or an equivalentforaminous filter media. This preferred filter media is a rigidopen-celled foam that is moldable, machinable, and otherwise workableinto any shape as deemed advantageous for a particular application. Mostpreferably, to optimize filtration but also to allow sufficient airflowrates, the preferred filter media has an average pore size in the rangeof 45 μm to 90 μm. As is shown in FIGS. 13A-13C, the filter H is mostpreferably formed in a convoluted or circuitous configuration tomaximize an outer surface area 112 of the filter. The maximized surfacearea 112 allows for the filter media to have a smaller pore size withoutunduly restricting the airflow therethrough. Most preferably, the filtermedia is formed into at least two elongated and concentric cylindersand/or frustums, 114a,114b with a deep annular passage 116 definedtherebetween. Preferably, a deep central passage 118 is defined in theinnermost cylinder or frustum 114a. However, it should be appreciatedthat other filter designs could also be used if so desired. For example,it is possible to use a filter element not having a deep centralpassage. FIG. 13D illustrates such an alternative configuration of themain filter element H′. Like components relative to the main filterelement 11 are identified with like numerals including a primed (′)suffix. The filter element H′ is formed by concentric cylindricalportions 114a′,114b′ separated by a deep annular passage 116′. However,unlike the main filter element H, the element H′ does not include a deepcentral passage formed in the inner cylindrical 114a′.

As mentioned the subject vacuum A also comprises a final filter assemblyF for filtering the suction airstream downstream from the motor/fanassembly and immediately prior to its exhaustion into the atmosphere.The preferred final filter assembly F is illustrated most clearly inFIG. 11 and comprises a suction airstream inlet 120 which is connecteddownstream and in fluid communication with the exhaust outlet 42 of themotor and fan assembly E. The inlet 120 is itself in fluid communicationwith an elongated plenum 122 that opens to the atmosphere and housesfilter media A protective grid or grate structure in snap-fit orotherwise effectively secured over the plenum 122 to secure the filtermedia in place. The filter media is preferably a high efficiencyparticulate arrest (HEPA) filter element in a sheet or block form. Thefilter media is retained in position in the plenum by the grid 124, butis easily replaced by removing the grid. As such, those skilled in theart will recognize that even if the motor/fan assembly causescontaminants to be introduced into the suction airstream downstream fromthe main filter element H, the final filter assembly F will remove thesame such that only contaminant-free air is discharged into theatmosphere.

Referring primarily to FIGS. 8 and 14, the operation of the vacuumcleaning apparatus A is illustrated, with the flow of the suctionairstream indicated by use of arrows J. The motor/fan assembly E orother suction generator establishes a suction force at its suction inlet42, in the elongated suction conduit 46, and thus in the cyclonicseparation chamber 54. This suction force or negative pressure in thechamber 54 is communicated to the main suction opening 26 formed in thenozzle underside 24 through the hoses 82,34 (FIG. 5) and associatedfittings. This, then, in combination with the scrubbing action of therotating brush assembly 36 causes dust and dirt from the surface beingcleaned to be entrained in the suction airflow J and pulled into theupper portion of the chamber 54 through the generally tangential inlet80.

The location of the inlet 80, the outlet passage 60, and the generallycylindrical configuration of the chamber 54 causes the suction airstreamto follow a swirling or cyclonic path downward within the chamber 54 andthen to move upward through a central portion of the chamber 54 towardthe centrally located main filter housing section 50b. The orientationof the inlet 80 will affect the direction of cyclonic airflow, and theinvention is not meant to be limited to a particular direction, i.e.,clockwise or counterclockwise. Those skilled in the art will certainlyrecognize that the term “cyclonic” as used herein is not meant to belimited to a particular direction of airflow rotation. This cyclonicaction separates a substantial portion of the entrained dust and dirtfrom the suction airstream and causes the dust and dirt to be depositedin the dirt cup or container 52. The suction airstream then passesthrough the apertures 56 formed in the main filter housing section 50b,passes through the main filter element H so that residual contaminantsare removed, and exits the cyclonic chamber 54 through the suctionairstream outlet passage 60 formed in the main filter housing section50a. The suction airstream is communicated to the motor/fan assembly Eand exhausted through the outlet 42 (as indicated by broken arrows) tothe final filter assembly F where it is filtered again by the HEPAfilter to remove any contaminants that passed through the chamber 54 andthe filter II, and any contaminants in the airstream due to its passagethrough the motor/fan assembly E.

The main filter element H can be cleaned by washing it, either manuallyor in a dishwasher—since it is dishwasher-safe—to remove dust or dirtparticles adhering to the filter element. It is, however, important thatthe filter H be dried before it is used again. The final filter media ofthe filter assembly F, however, can not be cleaned and must be replacedwhen it becomes clogged.

FIG. 15 illustrates a cyclonic airflow vacuum cleaner A′ in accordancewith a second preferred embodiment of the present invention. For ease ofunderstanding the invention, like components relative to the vacuumcleaner A are identified with like reference numbers and lettersincluding a primed (′) suffix, and new components are identified usingnew reference numbers and letters. Except as otherwise noted herein, andas is apparent from the drawings, the vacuum cleaner A′ is identical tothe vacuum cleaner A.

In particular, the vacuum cleaner A′ includes a modified cyclonicairflow dust and dirt separating region G′. As with the vacuum cleanerA, the cyclonic airflow region G′ includes a cyclonic airflow chamber54′ defined by an upper, fixed housing member 50a′ and a lower dirt cupor container 52′ which is previously and releasably connected to theupper housing B′ of the vacuum cleaner via a hinge assembly 90′. Withreference now to FIG. 19, the dirt cup 52′ includes a main filtersupport such as a post, stem, or like structure 150 extending upwardlyfrom a floor or base 152 thereof. The post 150 is positioned in acentral region of the cyclonic airflow chamber 54′. A hollow cylindricalmain filter element K is positioned over the main filter support 150.

The filter element K is engaged in an interference fit with vanes 154and a dime-like plateau 156 located on the floor 152 of the filtersupport so that the filter is releasably, yet securely, retained in itsoperative position as shown herein, even when the dirt cup 52′ isremoved from the vacuum cleaner and inverted for purposes of emptyingthe contents thereof. A filter locking means 158, accommodating a gasket159, is providing along the uppermost edge of the main filter element K.The main filter element K extends upwardly from the dirt cup floor 152to a level approximately equal to an upper edge 100′ of the dirt cup52′. Most preferably, as shown herein, the uppermost edge of the mainfilter element K is also sloped in the same manner as is the dirt cupupper edge 100′. Over the entire height of the dirt cup 52′, an annularcyclonic airflow passage is defined between the main filter support andthe dirt cup 52′.

It should be apparent from a comparison of FIGS. 19 and 15 that the base152 serves as the base of the dirt cup 52′. To this end, the base 152 issuitably secured by conventional means to the side walls forming thedirt cup.

The main filter element K preferably comprises the same filter media asthe filters H,H′. As shown herein , the filter element K is purelycylindrical in shape, but those skilled in the art will recognize thatthe filter element K may also be formed with a convoluted or otherirregular shape to increase its surface area and efficiency.

Referring now also to FIGS. 16-18, the upper housing member 50a′includes an upper conduit 160 depending centrally from a top wall 162.The upper conduit 160 is preferably a hollow cylindrical member with apassage 164 extending therethrough. The passage 164 is in fluidcommunication with the suction airstream outlet passage 60′ throughwhich the suction airflow J′ exits the cyclonic airflow chamber 54′. Theupper conduit 160 projects downwardly from the top wall 162 so that thelowermost edge 166 thereof is approximately equal to the level of thelower edge 102′ of the conduit member 50α′. Also, the lower edge 166 issloped in a manner that corresponds to the slope of the housing memberlower edge 102′. The upper conduit 160 is connected to the upper housingmember 50α′ by any suitable means such as fasteners engaged in alignedbores 168a,168b (FIG. 16) respectively formed in the housing member 50a′and conduit 160. As mentioned, the gasket 159 is provided along thejoint between the lowermost edge 166 of the upper conduit 160 and theupper edge of the filter K.

With reference now specifically to FIG. 18, an open or airstreampermeable auxiliary filter support grid or framework 170 is provided,preferably in the region of the lower edge 166 of the conduit 160. Theopen filter support 170 provides a backing member for a foam, paper, orsimilar conventional auxiliary filter element 174 that removes anyresidual dust and dirt from the suction airstream J′ prior to its exitof the cyclonic airflow chamber 54′ through the outlet passages 164 and60′. In case there is a break in the seal between the filter K, and theconduit 160, the auxiliary filter 174 will prevent dirt or dust frombeing sucked into the motor of the vacuum cleaner. One or more tabs orteeth 176 project radially inwardly from the conduit 160 in the regionof the framework 170 to engage the auxiliary filter element 174 so thatthe filter element is secured adjacent the framework 170 and will not bedislodged from its operative position by the force of gravity.

As is most readily apparent in FIG. 15, the main filter element K andthe upper conduit 160 together define a cylindrical column extendingthrough the center of the cyclonic airflow chamber 54′ between the floor152 and top wall 162. This preferred cylindrical column shape alsoresults from the filter element K and the upper conduit 160 havingsubstantially the same outside diameter.

As the suction airstream J′ enters the cyclonic chamber 54′ through thetangential inlet 80′, it travels downwardly in a cyclonic fashion sothat dust and dirt entrained in the suction airstream are separatedtherefrom and collected in the dirt cup 52′ (as indicated at L). Thesuction airstream J′ then passes through the main filter element K toremove residual contaminants therefrom, and moves upwardly through themain filter element K, through the auxiliary filter element 174, andinto the outlet passage 164. The airstream J′ is prevented frombypassing the main filter element K by the gasket 156 positioned betweenthe filter element K′ and the conduit 160. The airstream J′ then exitsthe cyclonic airflow chamber 54′ through the outlet passage 60′ andcontinues as described in relation to the vacuum cleaner A.

The position of the main filter element K, extending upwardly from thefloor 152, is highly desirable given that, as dust and dirt L arecollected, at least a portion M of the suction airstream passes throughthe accumulated dust and dirt L. The accumulation of dust and dirt Lseems to act as another filter element which filters more dust and dirtsfrom the airstream M. Also, the flow of the suction airstream Mdownwardly through the accumulated dust and dirt L acts to compact thedust and dirt L downwardly toward the floor 152 so that the capacity ofthe dirt cup 52′ is efficiently utilized to extend the time before thedirt cup 52′ must be emptied.

The invention has been described with reference to the preferredembodiments. Obviously, modification and alterations will occur toothers upon reading and understanding the preceding detaileddescription. It is intended that the invention be construed as includingall such modifications and alterations insofar as they come within thescope of the appended claims or the equivalents thereof.

1. A vacuum cleaner comprising: a housing having a cyclonic airflowchamber for separating contaminants from a suction airstream, saidhousing including a floor, a top wall, a suction airstream inlet, and asuction airstream outlet, said airstream inlet and said airstream outletbeing in fluid communication with said cyclonic airflow chamber; asuction opening defined on said housing, said suction opening beingfluidically connected with said airstream inlet; an airstream suctionsource located on said housing, said suction source having an inletfluidically connected to said airstream outlet and a suction sourceexhaust outlet, said suction source selectively establishing andmaintaining a suction airstream from said suction opening to saidsuction source exhaust outlet; a main filter support upwardly from thefloor of the housing for releasably accruing a main filter elementcentrally in said cyclonic airflow chamber; a main filter elementsecured to said main filter support; and, a dirt cap selectivelypositioned in said housing, said main filter element being positioned insaid dirt cup.
 2. The vacuum cleaner of claim 1 further comprising anupper conduit depending from said top wall and including an outletpassage therethrough in communication with the suction airstream outletof said housing, said upper conduit including a lower edge adapted forscalingly engaging the main filter element so that said upper conduitand said main filter element together define a column extending betweensaid floor and said top wall of said housing, whereby a suctionairstream passing through said cyclonic airflow chamber from saidsuction airstream inlet to said suction airstream outlet passes throughthe main filter element, into said upper conduit, and exits and chamberthrough said suction airstream outlet.
 3. The vacuum cleaner as setforth in claim 1 wherein said main filter element comprises high-densitypolyethylene porous filter media having pores with an average pore sizeof approximately 45 μm to approximately 90 μm.
 4. The vacuum cleaner asset forth in claim 1 wherein said housing is defined by an upper housingmember, wherein said upper housing member includes said top wall and anupper conduit depending from said top wall, and said dirt cup.
 5. Thevacuum cleaner of claim 4 wherein said dirt cup is pivotable between aclosed, operative position and an open position, said dirt cup includingsaid floor, said filter element extending upwardly from the floor andincluding an upper edge at a level substantially equal to an upper edgeof the dirt cup, and said upper conduit depending downwardly andincluding a lower edge at a level substantially equal to the upper edgeof said dirt cup, said vacuum cleaner further comprising a gasketdisposed between said filter element upper edge and said lower edge ofsaid upper conduit so that said main filter element and said lower edgeof the upper conduit sealingly mate in an airtight manner when said dirtcup is in the closed, operative position, wherein said upper edge ofsaid dirt cup is defined by an inclined edge such that when said dirtcup is pivoted fully into the open position, the inclined upper edge islocated in a substantially horizontal plane to inhibit spillage of theseparated dirt and dust.
 6. The vacuum cleaner as set forth in claim 2further comprising an auxiliary filter element positioned in said upperconduit, said auxiliary filter element being so positioned that airflowexiting said cyclonic airflow chamber through said upper conduit passestherethrough and is filtered of residual dust and dirt; and, anauxiliary filter support framework extending across an outlet passagedeclined in said upper conduit for supporting said auxiliary filterelement in a blocking relationship relative in said outlet passage ofsaid upper conduit.
 7. The vacuum cleaner as set forth in claim 1further comprising a final filter assembly positioned on the vacuumcleaner, said final filter assembly being in fluid communication withsaid suction source exhaust outlet for filtering said suction airstreamexhausted from said suction source exhaust outlet and for dischargingsaid suction airstream into the atmosphere.
 8. The vacuum cleaner as setforth in claim 7 wherein said final filter assembly comprises a highefficiently particulate arrest (HEPA) filter media.
 9. An upright vacuumcleaner comprising: an upright housing section including a handle; anozzle base section hingedly interconnected with the upright housingsection, said nozzle base section including a main suction openingformed in an underside thereof; a cyclonic airflow chamber defined insaid upright housing section for separating dust and dirt from a suctionairstream; a suction source located in one of said upright housingsection and said nozzle base section and having a suction airflow inletin fluid communication with said cyclonic airflow chamber and a suctionairflow outlet; and, a main filter element located in said cyclonicchamber upstream from said suction source for filtering residual dustand dirt from a suction airstream passing through said cyclonic airflowchamber, said main filter element extending upwardly within saidcyclonic airflow chamber from a floor of said housing section, wherein alower portion of said cyclonic airflow chamber is defined by a dirtcontainer for receiving and retaining dirt and dust separated from saidsuction airstream.
 10. The upright vacuum cleaner as set forth in claim9 further comprising a final filter assembly located on one of saidhousing and said nozzle base, said final filter assembly being connectedin fluid communication with said suction airflow outlet of said suctionsource for filtering said suction airstream exhausted by said suctionsource prior to said suction airstream being dispersed into theatmosphere, wherein said final filter assembly comprises a highefficiency particulate arrest (HEPA) filter media.
 11. The uprightvacuum cleaner as set forth in claim 9 wherein said main filter elementcomprises porous high-density polyethylene filter media.
 12. The uprightvacuum cleaner as set forth in claim 11 wherein said porous filter mediahas pores with an average pore size of less than approximately 90 μm.13. The upright vacuum cleaner as set forth in claim 11 furthercomprising an upper conduit depending from a top wall of said uprighthousing section, wherein said upper conduit includes an outlet passageformed therethrough in fluid communication with a suction airstreamoutlet of said cyclonic airflow chamber, said main filter elementsecured in a blocking relation with said outlet passage of said upperconduit so that said suction airstream passes through said main filterelement prior to existing said cyclonic airflow chamber.
 14. The uprightvacuum cleaner as set forth in claim 13 wherein said upper conduitincludes an auxiliary filter positioned in said outlet passage forfiltering residual dust and dirt from the suction airstream after thesuction airstream passes through said main filter element.
 15. Theupright vacuum cleaner as set forth in claim 13 wherein an upper end ofsaid main filter element is sealingly engaged with a lower end of saidupper conduit.
 16. A vacuum cleaner comprising: a nozzle section; ahousing section connected to said nozzle section and in fluidcommunication with said nozzle section; a cyclonic airflow chamberlocated in said housing section for separating dirt and dust from asuction airstream flowing into said housing section between an inletlocated at a periphery of said housing section and an outlet locatedalong a longitudinal centerline of said housing section; an upperconduit depending from a top wall of said cyclonic airflow chamber andincluding a passage therein in communication with said outlet of saidhousing section; and, a main filter element extending upwardly from afloor of said cyclonic airflow chamber in a central portion of saidchamber so that an annulus is defined between said main filter elementand the housing portion defining said chamber, said main filter elementsealingly engaged with said passage in said upper conduit and adaptedfor filtering residual dust and dirt from said suction airstream priorto said suction airstream exiting said cyclonic airflow chamber.
 17. Thevacuum cleaner of claim 16 wherein said housing section comprises a dirtcontainer defining a lower portion of said cyclonic airflow chamber andadapted for receiving and retaining dirt and dust separated from saidsuction airstream, said container being pivotable between an operativeposition and an open position and including an open upper end defined byan inclined edge such that when said dirt container is pivoted fullyinto the open position, the inclined edge is located in a substantiallyhorizontal plane to inhibit spillage of the separated dirt and dust. 18.The vacuum cleaner as set forth in claim 16 further comprising: a mainsuction opening located in said nozzle section and connected to asuction airstream inlet of said cyclonic chamber; and, a suction sourcelocated on said housing section, and connected to said outlet thereof,for suctioning an airstream from said nozzle main suction opening intoand through said cyclonic chamber to an exhaust outlet of said suctionsource.
 19. The vacuum cleaner as set forth in claim 18 furthercomprising a final filter chamber connected to said exhaust outlet ofsaid suction source and a final filter element for filteringcontaminants from said airstream exhausted by said suction source. 20.The vacuum cleaner as set forth in claim 19 wherein said final filterelement comprises high efficiency particulate arrest filter media. 21.The vacuum cleaner as set forth in claim 16 wherein said main filterelement comprises high density polyethylene porous filter media havingan average pore size of approximately 45 μm to approximately 90 μm. 22.The vacuum cleaner as set forth in claim 16 wherein a portion of saidsuction airstream in said cyclonic airflow chamber passes throughaccumulated dust and dirt separated from said suction airstream so thatsaid accumulated dust and dirt acts as a filter media to separateresidual dust and dirt from said portion of said suction airstream priorto said portion of said suction airstream passing through said mainfilter element.
 23. A vacuum cleaner comprising: a body section having acyclonic airflow chamber for separating contaminants from a suctionairstream; a suction opening communicating with said body section, saidsuction opening being fluidly connected to said cyclonic airflowchamber; a main filter housing connected to said body section, said mainfilter housing being located within said cyclonic airflow chamber; afilter element mounted in said main filter housing, wherein said mainfilter housing comprises a plurality of apertures so that an airstreamcan flow from said cyclonic airflow chamber into said main filterhousing; and, an airstream suction source located on said body section,and suction source communicating with said main filter housing.
 24. Thevacuum cleaner of claim 23, wherein at least a portion of said mainfilter housing is selectively detachable from said body section.
 25. Thevacuum cleaner of claim 24, wherein said filter element is selectivelyretained within said at least a portion of said main filter housing. 26.The vacuum cleaner of claim 24, wherein said at least a portion of saidmain filter housing comprises at least one tab extending therefrom,wherein said at least one tab of said at least a portion of said mainfilter housing cooperates with adjacent elements mounted on said bodysection to secure said at least a portion of said main filter housing tosaid body section.
 27. The vacuum cleaner of claim 24, wherein said mainfilter housing comprises an airflow outlet which communicates with saidairstream suction source.
 28. The vacuum cleaner of claim 23, whereinsaid filter element is approximately frusto-conical in shape.
 29. Thevacuum cleaner of claim 23, wherein said filter element comprises athermoplastic material.
 30. The vacuum cleaner of claim 23, wherein saidmain filter housing comprises a closed bottom end.
 31. The vacuumcleaner of claim 30, wherein said bottom end of said main filter housinghas a diameter that is larger than is a diameter of an adjacent portionof said main filter housing.
 32. A vacuum cleaner comprising: a nozzlebase; an upright body section pivotably mounted on said nozzle base; acyclonic airflow chamber defined in said upright body section, whereinsaid cyclonic airflow chamber comprises an airflow inlet and an airflowoutlet; a suction opening defined in said nozzle base, said suctionopening being fluidly connected with said airflow inlet of said cyclonicchamber; an airstream suction source located on one of said nozzle baseand said upright body section, said suction source having an inletfluidly connected to said airflow outlet of said cyclonic chamber and anexhaust outlet; a main filter housing connected to said upright bodysection, said main filter housing being located within said cyclonicairflow chamber; and, a filter element mounted in said main filterhousing, wherein said main filter housing comprises a plurality ofapertures so that an airstream can flow from said cyclonic airflowchamber into said main filter housing.
 33. The vacuum cleaner of claim32, wherein said airflow outlet of said cyclonic airflow chamber iscoaxial with a longitudinal axis of said cyclonic airflow chamber. 34.The vacuum cleaner of claim 32, wherein said filter element issubstantially coaxial with a longitudinal axis of said cyclonic airflowchamber.
 35. The vacuum cleaner of claim 32, wherein said airflow inletof said cyclonic airflow chamber is tangential to a longitudinal axis ofsaid cyclonic airflow chamber.
 36. The vacuum cleaner of claim 32,further comprising a conduit fluidly connecting said suction opening ofsaid nozzle base with said airflow inlet of said cyclonic airflowchamber.
 37. The vacuum cleaner of claim 32, wherein at least a portionof said main filter housing is selectively detachable from said uprightbody section.
 38. The vacuum cleaner of claim 37, wherein said filterelement is selectively retained within said at least a portion of saidmain filter housing.
 39. The vacuum cleaner of claim 32, wherein saidmain filter housing comprises an airflow outlet which communicates withsaid airstream suction source.
 40. The vacuum cleaner of claim 32,wherein said filter element is approximately frusto-conical in shape.41. The vacuum cleaner of claim 32, wherein said filter elementcomprises a thermoplastic material.
 42. A vacuum cleaner comprising: abody section having a cyclonic airflow chamber for separatingcontaminants from a suction airstream; a suction opening defined on saidbody section, said suction opening being located upstream from saidcyclonic airflow chamber and communicating therewith; an airstreamsuction source located on said body section, said suction source beinglocated downstream from said cyclonic airflow chamber and communicatingtherewith; a main filter housing located within said cyclonic airflowchamber; and, a filter element mounted in said main filter housing,wherein said main filter housing comprises a plurality of apertures sothat an airstream can flow from said cyclonic airflow chamber throughsaid filter element and toward said airstream suction source.
 43. Thevacuum cleaner of claim 42, further comprising a dirt cup, wherein saidcyclonic airflow chamber is at least partially located within said dirtcup.
 44. The vacuum cleaner of claim 43, wherein said main filterhousing is arranged substantially coaxial with a longitudinal axis ofsaid dirt cup.
 45. The vacuum cleaner of claim 42, wherein said mainfilter housing is arranged substantially coaxial with a longitudinalaxis of said cyclonic airflow chamber.
 46. The vacuum cleaner of claim42, wherein said cyclonic airflow chamber comprises an airflow outletwhich is substantially coaxial with a longitudinal axis of said cyclonicairflow chamber.
 47. The vacuum cleaner of claim 42, wherein saidcyclonic airflow chamber comprises an airflow inlet which issubstantially tangential to a longitudinal axis of said cyclonic airflowchamber.
 48. The vacuum cleaner of claim 47, further comprising aconduit fluidly connecting said suction opening of said body sectionwith said cyclonic airflow chamber.
 49. The vacuum cleaner of claim 42,wherein said filter element is approximately frusto-conical in shape.50. The vacuum cleaner of claim 49, wherein said filter elementcomprises a thermoplastic material.
 51. The vacuum cleaner of claim 42,wherein at least a portion of said main filter housing is selectivelydetachable from said body section, thereby allowing access to saidfilter element.
 52. A vacuum cleaner comprising: a body section having acyclonic airflow chamber defined therein; a suction opening defined onsaid body section, said suction opening being located upstream from saidcyclonic airflow chamber and communicating therewith; a main filterhousing located within said cyclonic airflow chamber; a filter elementselectively mounted in said main filter housing a wherein said filterelement and said main filter housing cooperate to define a tortousairflow path; and, an airstream suction source located on said bodysection, said suction source being located downstream from said cyclonicairflow chamber and communicating therewith.
 53. The vacuum cleaner ofclaim 52, wherein said cyclonic airflow chamber comprises an airflowoutlet, wherein said main filter housing is located adjacent saidairflow outlet.
 54. The vacuum cleaner of claim 53, wherein said mainfilter housing comprises a plurality of apertures so that an airstreamcan flow from said cyclonic airflow chamber into said main filterhousing, through said filter element and toward said airstream suctionsource.
 55. The vacuum cleaner of claim 53, wherein said airflow outletof said cyclonic airflow chamber is substantially coaxial with alongitudinal axis of said cyclonic airflow chamber.
 56. The vacuumcleaner of claim 52, further comprising a dirt cup mounted in said bodysection, wherein said cyclonic airflow chamber is at least partiallylocated with said dirt cup.
 57. The vacuum cleaner of claim 56, whereinsaid main filter housing is arranged substantially coaxial with alongitudinal axis of said dirt cup.
 58. The vacuum cleaner of claim 52,wherein said main filter housing is arranged substantially coaxial witha longitudinal axis of said cyclonic airflow chamber.
 59. The vacuumcleaner of claim 52, wherein said cyclonic airflow chamber comprises anairflow inlet, said airflow inlet being substantially tangential to alongitudinal axis of said cyclonic airflow chamber.
 60. The vacuumcleaner of claim 52, wherein at least a portion of said main filterhousing is selectively detachable from said body section.
 61. The vacuumcleaner of claim 60, wherein said at least a portion of said main filterhousing comprises tabs and is rotated to selectively detach said atleast a portion of said main filter housing from said body section. 62.The vacuum cleaner of claim 60, wherein said filter element isselectively held in said at least a portion of said main filter housing.63. The vacuum cleaner of claim 52, wherein said filter element isapproximately frusto-conical in shape.
 64. The vacuum cleaner of claim63, wherein said filter element comprises a thermoplastic material. 65.The vacuum cleaner of claim 52, wherein said main filter housingcomprises a closed bottom end.